Lightning arrester



Feb. 28, 1933. H M TQWNE 1,899,540

LIGHTNING ARRESTER Filed Sept. 11, 1931 Ihvehtor Harold M. Towhe,

His Attorney.

Patented Feb. 28, 1933 UNITED STATES PATENT OFFICE.

HAROLD I. TOWNE, OI PITTSFIELD, IABSAO'KUBETN- ASSIGNOB TO GENERAL ELECTRIC CORANY, A CORPORATION OF NEW YORK LIGHTNING ABBEBTEB Application fled September 11, 1981.

My invention relates to lightning arresters and particularly to arresters for the protection of low voltage electrical circuits such as may be used in connection with the operation and control of signals, relays and other small electrical apparatus. The general ob- .ject of the invention is to provide a simple and reliable arrester of this type. Another object is to provide an arrester having an improved over-voltage discharge element which may be easily and quickly repaired or relaced after its efficiency has been impaired y an electrical discharge.

Other objects and advantages will appear from the following description taken in connection with the accompanying drawing in which Fig. 1 is a perspective view of a lightning arrester constructed in accordance with the invention; Fig. 2 is a longitudinal sectional view of the arrester; Fig. 3 is a plan View of the arrester; Fig. 4 is a sectional View of the 'discharge element of the arrester; Fig. is an exploded view showing the vari one component parts of the discharge element, and Fig. 6 is a view of several arresters showing how they may be mounted in a group and connected to the circuits which they are to protect.

Like reference characters indicate similar parts in the difierent iigures'of the drawing.

The arrester, as shown in the drawing, has an eiongated base if of insulating molded material on which is. mounted a row of three binding posts 11, i2 and 13, the posts 11 and 13 being mounted near opposite ends of the base 10 the post 12 being mounted between the two posts 11 and 13. The bases of two springs 14 and 15 are secured by the osts 11 and 12 respectively in depressions in the upper surface of the base 10. These springs 14 and 15 have resiliently spaced blades 16 and 17 respectively which extend on both sides of the space between the binding posts 11 and 12. A discharge unit 18 is removably held between the blades 16 and 17 of the springs.

The discharge unit 18 includes a hollow insulating casing formed in two sections 19 and 20 which have peripheral rims on their ad- Serlal No. 562,317;

jacent faces, the rims being threaded so that the two sections may be screwed together and held rigidly with their inner faces in desired spaced relation. Two springs 21 and 22 are secured at their centers by rivets 23 and 24 respectively to the inner faces of the two sections 19 and 20 of the casing 18, and a discharge element is held between these two springs. This discharge element may be of any desired type, but is shown in the drawing as including two carbon blocks 25 and 26 separated by a thin mica spacer 27 to provide a small air gap between the two blocks. The

ductor 9 in the base 10 of the arxester. Thus,

the binding posts 11 and 13 ar ductively with the carbon center bindzn post 12 is co;

connected conct; 25 and the acted conductively with the dthcr carbon block 26. \Vhen the arrester is in use. the binding oostii? is grounded as shown in Fig. 6. I

A circuit to otected may be connected either to the i: ling post 11 or to the bind ing port 13, to both. If the oltage of the protected circuit becomes excessive and unsafe, a discharge Wil. he place through the binding post 11 01113- the. sprin is and blade 16, the rivet 23 d its 1.1g 21, the carbon hiocks a: 2h the air gap be tween them, s; \o its rivet 24, the spring 15, and ding post 12 to ground.

one The air'gap between the carbon blocks 25 and 26 norma y insulates the protected circuit from ground but is broken down by the excessive voltage to permit the discharge the windings 31 and 32in Fig. 6, may be connected to the corresponding binding osts 13. The binding osts 12 are 'connecte together by the con uctive links 33 and con- 5 nected to the ground 34. One side of each circuit is thus rounded through the spring blade 17 and toe other side is connected to "the spring blade 16 so that the discharge unit '18 will prevent excessive potentials across the windings 31 and 32.

The invention provides an arrester with a simple discharge unit which may be very easily and conveniently inspected and cleaned or replaced in case it becomes short circuited.

The invention has been explained by illustrating and describing a particular form thereof, but it will be ap arent that changes may be made without eparting from the spirit of the invention or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is 1. In a discharge unit for an arrester, en insulating casing formed in two sections,

2 and a spring secured to the inner face of each casing I section by a rivet, whereby a discharge element may be held between said springs, the rivets extending through the casin sections to form external contacts.

2. n a dischar e unit for an arrester, an insulating casing ormed in two sections with peripheral rims, said rims being threadedtogether to secure saidcasing sections in spaced relation, and a spring-secured to the inner face of each casing section by e rivet,

whereby a discharge element may be held between said springs, the rivem extendin through the casing sections to form exte contacts. 1

to In witness whereof, I have hereunto set my hand.

HAROLD M. TQ 

